Tilt sensor and method of making same

ABSTRACT

An apparatus and method of making the same for sensing inclination. The apparatus includes a member moveably positioned in a body, the member moves in response to gravity between two positions if the body is rotated relative to an axis exceeding a certain amount. A detector can be used to detect when the member moves and can automatically report rotation. A method of making an inclinometer includes creating the body by laminating layers, where a layer is prefabricated to include an appropriate cut-out to guide the member between the two positions. Another layer or layers can include the detector. An aspect of the invention comprises having each layer include prefabricated features for multiple inclinometers, and then superposing the prefabricated layers, activating adhesive between them to form a lamination defining a plurality of inclinometers, and then separating the lamination into individual inclinometers.

BACKGROUND OF THE INVENTION

[0001] In many instances it would advantageous or desirable to know theorientation of an object relative to a fixed parameter, e.g. earth'shorizon. Still further, automatic or autonomous sensing of orientationmany times be can beneficial.

[0002] For example, it has been found desirable to sense whether adigital camera is tilted left or right relative to the horizon. Awarning can be given to the user (e.g. in case such orientation isinadvertent), or the logic of the camera can otherwise utilize thisinformation.

[0003] A variety of tilts sensors (sometimes called inclinometers)exist. Many provide automatic information about angle of an object withrespect to gravity. Many are configured to report exact angle relativeto horizon. There are instances where such exactness is demanded.However, such configurations tend to be complex and expensive, and canbe relatively large in size. They also attend to be more susceptible toerror or damage because of sensitivity of components.

[0004] There is a need for robust, economical automatic sensors of atleast general positional orientation. There is also a need forrelatively small sensor size.

[0005] In the example of digital cameras, attempts have been made toinstall tilt sensors inside the camera. One example uses a componentthat works adequately to automatically indicate substantial tiltrelative to one axis. However, it lacks robustness, particularly in thesense that once installed in the camera and integrated with the digitalcamera circuitry, it may not pass or survive manufacturing or assemblysteps (e.g. soldering—it may not pass or function correctly after soldercleaning tests). Its accuracy or functioning may be affected, andtherefore, a potential deficiency exists with this type of tilt sensor.

[0006] A need has therefore been identified in the art. It is thereforea principal object, feature, and advantage of the present invention toprovide a tilt sensor and method of making the same which solves theproblems and deficiencies in the art, and/or improves over the state ofthe art.

[0007] Other general objects, features, and/or advantages of theinvention can include:

[0008] a. relatively non-complex structure.

[0009] b. robustness and durability.

[0010] c. economy, both as a discrete tilt sensor, as well as in amethod of manufacturing a plurality of tilt sensors.

[0011] d. efficiency, including size, number of moving parts, powerconsumption, and operability.

[0012] e. ability to produce a digital feedback.

[0013] These and other objects, features, and advantages of the presentinvention will become more apparent with reference to the accompanyingspecification and claims.

BRIEF SUMMARY OF THE INVENTION

[0014] The invention includes a tilt sensor having a body, a space inthe body, and a member positionable in the space, the member moveablebetween at least two positions within the space under the influence ofgravity when the body is rotated about an axis, and a detector in thebody to detect when the member is in one of the two positions. A methodof manufacturing tilt sensors comprises forming the body out of alamination, one lamination layer defining an interior open space for themember to move between the at least two positions, and additionallamination layers that are positioned on opposite sides of thelamination layer with the member positioned in the space, to contain themember. Additional lamination layers can be utilized. On at least one ofthe lamination layers, a detector can be positioned and, if electricalor electronic, electrical connections can be integrated, created ormounted onto the lamination layers.

BRIEF DESCRIPTION OF THE DRAWINGS

[0015]FIG. 1 is a perspective view of a device according to the presentinvention shown affixed inside and onto the rear wall of a digitalcamera (shown in broken lines).

[0016]FIG. 2A is an enlarged perspective view of the tilt sensor of FIG.1 from a slightly different angle and separated from the camera.

[0017]FIG. 2B is a perspective view of the opposite side of the deviceof FIG. 2A.

[0018]FIG. 2C is a reduced-in-size perspective view similar to FIG. 2Abut illustrating the tilt sensor attached to a surface.

[0019]FIG. 3 is a sectional view taken along line 3-3 of FIG. 2A.

[0020]FIG. 4 is a section taken along line 4-4 of FIG. 2A.

[0021]FIG. 5 is an electrical schematic of the electrical circuitry foran exemplary embodiment of the invention.

[0022]FIG. 6 is a schematic diagram of a recommended PCB solder padfootprint for electrical connection of the exemplary embodiment of theinvention to another device.

[0023]FIG. 7 is an enlarged sectional view similar to FIG. 3diagrammatically illustrating the tilt sensing function of the exemplaryembodiment. FIGS. 8A-G are diagrammatical perspective illustrations ofpre-fabricated panels in preparation for manufacturing a plurality ofsensors by assembling the panels into a lamination.

[0024]FIG. 9 is a diagrammatic perspective illustration of a method forcreating a lamination of the panels of FIGS. 8A-G.

[0025]FIGS. 10A and B are illustrations of an alternative embodimentaccording to the present invention.

[0026]FIGS. 11A and B are illustrations of another alternativeembodiment according to the present invention.

[0027]FIGS. 12A and B are illustrations of another alternativeembodiment according to the present invention.

[0028] FIGS. 13-15 are illustrations of a still further alternativeembodiments according to the present invention.

DETAILED DESCRIPTION OF THE INVENTION

[0029] A. Overview

[0030] To assist in a better understanding of the invention, onespecific exemplary embodiment will now be described in detail. Frequentreference will be taken to the appended drawings. Reference numerals andletters will be used to indicate certain parts and locations in thedrawings. The same reference numerals or letters will be used toindicate the same parts or locations throughout the drawings unlessotherwise indicated.

[0031] B. General Environment of Exemplary Embodiment

[0032] The present invention relates to a tilt sensor. In this exemplaryembodiment, it will be discussed in conjunction with a digital camera,serving the function to produce and report automatically if the digitalcamera is tilted to the left or to the right greater than a certainrotational angle. As can be appreciated, this autonomous automaticreporting can be beneficial and useful. It is to be understood, however,that this is but one example of application of the tilt sensor accordingto the invention and does not limit its application to this environment.

[0033] C. Basic Structure and Operation

[0034]FIG. 1 illustrates a tilt sensor 10 according to the presentinvention attached (by adhesives or other methods) to the inside backwall of digital camera 12. For purposes of discussion, the back wall ofcamera 12 will be considered generally planar, and defined by the axes Xand Y in FIG. 1.

[0035] The front wall of the camera will be designated by referencenumeral 16. The axis Z, orthogonal to the X-Y plane, is also shown inFIG. 1. The X-Y plane therefore generally depicts a vertical plane ofthe camera. The Z-axis is generally aligned with the aiming axis of thelens of camera 12.

[0036] Sensor 10 has a body that includes an external set of electricalcontacts 32. As can be appreciated, and as is well-known in the art,these electrical contacts can be configured to be connectable toelectrical conductors in digital camera 12 that can communicateelectrical power to tilt sensor 10 and communicate output from tiltsensor 10 to camera 12. The solder pad footprint configuration of FIG. 6illustrates a connection interface to the digital camera.

[0037] Sensor 10 is configured so that it will generate an output signalfrom which can be derived whether camera 12 is rotated around axis Z ineither the left or right direction (see arrow 18 in FIG. 1) on the orderof 90 degrees or more in either direction. Camera 12 can utilize thisinformation to alert the operator, store such information with anydigital picture data that might be taken when the camera is in thatorientation, or for other uses.

[0038] FIGS. 2A-C, and FIGS. 3-6, show a specific exemplary embodimenttilt sensor 10 in more detail. As indicated in FIG. 2A, tilt sensor 10can be on the order of 0.2 inches tall, 0.3 inches long, and 0.15 inchesthick. In this relatively small package, contained in substantiallysealed fashion, are the inner-workings for the tilt sensor.

[0039] The tilt sensor body has a front 20, a left side 22, right side24, back 26, bottom 28, and top 30. As mentioned, in this embodiment,top 30 includes a plurality of electrical contacts 32 of electricallyconducting material, namely ground 34, left output 36, LED voltage IN38, right output 40, and ISO (electrically isolated) voltage IN 42 (e.g.standard DC operating voltage such as 5 VDC or 3.3 VDC) (see FIG. 5).Contacts 34, 36, 38, 40, and 42 are configured such that they areadapted to be easily electrically connected to electrical circuitry ofdigital camera 12.

[0040]FIG. 2C illustrates tilt sensor 10 isolated on a X Y plane (e.g.back wall 14 of digital camera 12). This will be called the generalreference position of tilt sensor 10. When sensor 10 is in the referenceposition, the X-axis and the longitudinal axis of tilt sensor 10 (itslongitudinal axis is between left and right sides of sensor 10 andbetween and parallel to the front and back walls 20 and 26 of tiltsensor 10) is generally parallel to horizontal.

[0041] Internally, stainless steel balls 60L and 60R are captured inelongated ball tracks or races 50L and 5OR respectively (see inparticular FIGS. 3 and 4). These tracks or races 50 are configured to beat approximately 55 degrees angles to the X-axis or longitudinal axis ofsensor 10, but extend in different directions, as shown in FIG. 3. Eachrace 50 is sized and configured to allow its ball 60 to freely move(after overcoming the coefficient of friction between ball 60 and thestructure defining its race) between a bottom or lower end 52 and upperend 54, but restrain any movement other than along the longitudinal axisof that track 50. In other words, the structure that defines the openarea, space, or channel comprising race 50 completely surrounds ball 60but allows it to roll or slide between opposite ends 52 and 54. Balls 60are solid stainless or chromed steel (0.062 or {fraction (1/16)}^(th)inch diameter). Tracks 50 are approximately {fraction (1/10)}^(th) inchlong. Race 50 is sized such that ball 60 can not move other than alongthe longitudinal axis of race 50 (between ends 52 and 54). There can bea small tolerance between the diameter of ball 60 and the diameter ofrace 50 (e.g. approximately 0.005 to 0.008 inch). If a ball 60completely overcomes the coefficient of friction of any structure it iscontact with, it can slide—as opposed to roll. In this embodiment, thestructure defining race 50 is an epoxy glass material which is quitehard and smooth, and therefore has a relatively low coefficient offriction.

[0042] As shown most clearly at FIG. 4, LED emitter 62 and photodetector 68 are placed on opposite lateral sides of upper end 54 of eachtrack 50. Openings 64 and 66, through intermediary structure in sensor10, provide an unobstructed path between each LED 64 and photo detector68 set, except if ball 60 intervenes.

[0043] As shown in FIG. 2C, with device 10 essentially horizontal (inits reference position), balls 60L and 60R would be forced by gravity tothe lower end 52 of their respective ball track 50. Neither ball 60L or60R would obstruct the path between its respective LED 62 and opticaldetector 68 pair. Tilt sensor 10 would thus be in what will be called anormal or reference position.

[0044] By referring to FIG. 7, the way in which tilt sensor 10 canreport tilted position is diagrammatically illustrated. In FIG. 7, asingle tilt sensor is illustrated in three positions. A first position(indicated by reference number 10) shows tilt sensor 10 in the referenceor normal position, with its longitudinal axis essentially parallel tohorizontal. Balls 60L and 60R are (by gravity) in the bottom of theirrespective ball tracks 50L and 50R, and photo optical detectors 68L and68R are unobstructed.

[0045] Balls 60L and 60R will, by gravity, remain towards the lower partof ball tracks 50L and 50R, until one of the tracks 50L or 5ORapproaches and then passes horizontal, such that its upper end 54 isbelow a horizontal plane through its lower end 52. This occurs whensensor 10 is tilted or rotated generally in the direction of arrow 70 inFIG. 7 over 55 degrees relative its Z axis (which would extendorthogonally out of the page of FIG. 7). At that point (see depiction ofsensor at reference numeral 10′ in FIG. 7), where device 10 is tiltedenough to the right, just ball 60R′ will begin rolling or sliding bygravity towards the upper end of ball track 50R′ (assuming ball 60Rovercomes the coefficient of friction or is forced by gravity to roll)(see arrow 72 in FIG. 7). On the other hand, even though sensor 10 istilted, ball 60L′ will remain in the bottom of its ball track 50L′.Rotation well past 55 degrees (closer to 90 degrees) (see depiction ofsensor at reference numeral 10″ in FIG. 7) will cause ball 60R″ to rollor slide all the way to end 54 of ball track 50R″, which will blockopening 66R″ and thus block the corresponding photo optical detector 68R″. In this manner, tilt sensor 10 will interrupt the beam of infrared(IR) light energy from LED 64R, which will be detected by photo detector68R, thus providing automatic indication that can be output from device10 indicating that tilt sensor 10 has been rotated around the Z axisapproximately or towards 90 degrees. This signal can be utilized bydigital camera 12 as previously explained.

[0046] Thus, sensor 10 can give feedback about rotation or roll left orright of camera 12 around the Z axis. This assumes that camera 12 is notsubstantially pitched fore or aft (i.e. rotated about the X axis). Yaw(rotation around the Y axis, is generally irrelevant).

[0047] Note that even in an approximate 90 degree rotational position(reference numeral 10″ in FIG. 7), ball 60L does not move from its lowerposition in its ball track 50L. But, as can be appreciated, rotation oftilt sensor 10 in the opposite direction around the Z axis past 55degrees would cause ball 60L to roll or slide to the opposite end of itsball track 50L and block photo optical detector 68L, whereas ball 60would not block photo optical detector 68R, allowing tilt sensor 10 toproduce an output signal indicating a rotation or tilt in that opposite(in this example the left) direction of on the order of 90 degrees.

[0048] In this embodiment, LED's 62 are infrared (IR) LEDs (e.g. model #T 9511 VA available from Vishay Infrared Components, Santa Clara,Calif.—e.g. 800 NM IR LED having physical size that can surface mountwithin the space indicated in FIG. 4). Photo optical detectors 68 arephoto sensitive IC's with Schmitt triggers (e.g. model # T 2271 PIC fromVishay Infrared Components—e.g. physical size to fit within the spaceindicated in FIG. 4 and triggering off of the wavelength of radiationemitted by LED 62). Device 10 can be considered a two channelinterruptive tilt sensor or inclinometer which can provide digitalfeedback to a digital camera of its general orientation relative to thenatural horizon of earth. Feedback is provided through the use of thesteel balls 60 that self-position themselves relative to gravity andinterrupt the light that couples the two optical components 62 and 68 inany one channel. Depending on the orientation of the device 10 (and thusthe object to which it is attached), the balls 60 either allow lightfrom the IR LED 62 to couple with its respective photo sensitive IC 68or block the light to decouple the two active components within thechannel related to the side of inclination. Of course, detector 68 wouldhave a trigger threshold which is a function of amount of light that isgathered by it.

[0049] LED's 62 and photo detectors 68 are aligned across from eachother so that when the LED 62 is on, light travels through device 10through the two apertures 64 and 66. Being a normally high device, whenlight falls incident on the photo sensitive area of photo detector 68,the Schmitt Trigger changes state and the signal is switched to low. Asthe device 10 is rotated, a steel ball 60 is forced (via gravity) to theend of its channel or track 50, covering the respective apertures orholes 64 and 66, and blocking the light from its corresponding LED 62.The Schmitt Trigger changes state to high. In this manner, device 10 candetect an approximate 90 degree rotation in either the left or the rightdirection. It is therefore a single axis tilt sensor. It can provide adigital representation of tilt in opposite directions relative an axis.

[0050]FIG. 5 diagrams the basic electrical circuitry of device 10. Ofcourse, other ways are possible. Electrical power (+2.5 to 5.5 VDC) forLED's 62 and detectors 68 (LED VCC and ISO VCC—filtered to provide aclean incoming line, e.g. high or low band pass filtered to eliminateripple) would be provided from the battery source of camera 12. Thestate of detectors 68 can be discerned at OUT L and OUT R.

[0051] Method of Construction

[0052] The exemplary embodiment of device 10 is a printed circuit board(PCB) laminated structure consisting of seven layers of black (opaque)FR4 epoxy glass PCB material having a Tg of approximately 150 degreesCelsius. This is indicated most clearly at FIG. 4.

[0053] A first layer will be called race PCB 86, and comprises arelatively thick layer of PCB (slightly bigger than the diameter of ball60) of the general perimeter dimensions of device 10 and in which arepre-formed ball tracks 50L and 50R. On either side of race PCB 86 iswhat will be called aperture PCBs 84 and 88 of like perimeter dimensionsto layer 86 but, here, of smaller thickness. Aperture PCB 84 containsopenings 66 (smaller than ball 60) pre-formed and positioned tocorrespond with the placement of photo detectors 68. Aperture PCB 88includes pre-formed openings 64 (smaller than ball 60) positioned tocorrespond with LEDs 62. Aperture PCBs 84 and 88 also serve to containballs 60L and 60R in their respective tracks or races 50 once layers 84,86 and 88 are assembled.

[0054] Spacer PCBs 82 and 90 are positioned on the exterior sides ofaperture PCBs 84 and 88 respectfully and have pre-formed openings whichcorrespond to and provide space for photo detectors 68 and LEDs 62,which extend inwardly from the outer detector PCB 80 and LED PCB 92respectively, which complete the seven layer lamination make-up the bodyof device 10. Thus, the only moving parts are balls 60L and 60R. Thematerials making up the body are relatively economical (PCB). Theoptical components are secured by methods known in the art and arenon-moving. The laminated structure basically encapsulates the workingcomponents and the moving components. Once constructed, the body is notnecessarily completely or hermetically sealed, but it is adequatelyenclosed and encapsulated at least for, e.g., use inside a digitalcamera.

[0055] But further, this lamented structure can be efficiently andeconomically implemented in a manufacturing process that canconcurrently fabricate a plurality of devices 10, as described below. Asis diagrammatically illustrated at FIG. 8, the features of each layer80, 82, 84, 86, 88, 90, 92 of a single sensor 10 can be replicated aplurality of times in large layers or panels 180, 182, 184, 186, 188,190, 192, of the same material and thickness as layers 80, 82, 84, 86,88, 90, 92.

[0056] As it indicated in FIG. 8A, for example, each of the seven largepanels 180, 182, 184, 186, 188, 190, 192 could be partitioned or dividedinto sections each having the perimeter dimensions of approximately onedevice 10. Here, starting in the upper left-hand coner of the diagram ofFIG. 8, a first section of each large panel can be indicated as portioni1 j1. A second section in the first row is indicated as i1 j2. The lastequivalent section in the first row is i1 jN.

[0057] The plurality of columns can be repeated from i1 to iM. Bymethods well-known in the art, each of the seven layers can bepre-fabricated to contain either the electrical or photo electricalcomponents and associated printed circuits to operate the same, and/orpre-cut openings or other contour.

[0058] For example, the two photo diodes 68 needed for a single tiltsensor 60 can be pre-installed on each portion i1j1 to iMjN of largepanel 180 (see FIG. 8A). Printed circuits needed to supply electricalcommunication from these two photo detectors 68 to outputs 36 and 40 canbe pre-printed on that layer 80. Conventional surface mount (SMT)techniques can be used for mounting the optical components to theirsubstrates or panels. In this example, LEDs 62 and detectors 68 are dieattached and wired bonded to their respective panels 180 and 192. As canbe appreciated, a pair of detectors 68 can, by automation, be installedat the appropriate location on each section iX jY of large panel 180 andthe appropriate printed circuit, by automation, also installed accordingto standard PCB and SMT fabrication techniques.

[0059] Still further, the architecture of the electrical components andcircuitry fabricated onto panel 180 can be as shown in FIG. 8A; a pairof photodetectors 68 and associated printed circuit on each section i1j1to i1jN (the first row i1 of panel 180) with the electrical lines allterminating at the junction with its adjacent section in row i2. Therelative position of elongated ball tracks 50L and R are shown in ghostlines in FIG. 8A to indicate how the position of detectors 68 wouldalign therewith.

[0060] Then, each section i2j1 to i2jN is basically a mirror-image ofits corresponding adjacent section in row i1, with electrical lines alsoterminating at the junction between sections. That combination of diodesand printed circuits can then be repeated and replicated on succeedingadjacent pairs of rows for the entire large panel 180, to fill up panel180 as shown in FIG. 8A. This can be advantageously used to simplify theformation of final electrical connections 34, 36, 38, 40, and 42 foreach sensor 10, as will be explained later.

[0061] As shown in FIG. 8B, similarly the pair of openings 74L and R and75 for spacer PCB 82 for a single sensor 10 can be pre-fabricated (cutout) and repeated in each section i1j1 to iMjN of large panel 182.Openings 74 and 75 could be prefabricated by well known automatedtechniques for cutting shaped openings in wafers or PCBs. FIG. 8B onlyshows two pairs of openings (in sections i1j1 and i2j1), but openings74L and R would be plotted and cut out in each section on panel 182 toalign with ball tracks 50L and R (see ghost lines of ball tracks 50L andR).

[0062] The openings 66 and 67 in aperture PCB 84 can be pre-fabricatedand repeated an all positions i1j1 through iM jN for large panel 184(see FIG. 8C). Again, only two sets of apertures (in sections i1j1 andi2j1). Each section iXjY would have them appropriately positioned andpre-formed.

[0063] Races 50R and 50L could be pre-fabricated and repeated for eachsection i1j1 to iMjN of large panel 186; and so on for large panels 188,190, and 192 (with LEDs and associated printed circuits surface mountedto panel 192 in a similar manner to the detectors and associatedcircuits of panel 180). Again for layers 186, 188, 190, and 192, thepre-fabricated openings or surface mounted structure are shown onsections i1j1 and i2j1 only, but would be prefabricated for each sectioni1j1 to iMjN.

[0064] Once all large panels 180, 182, 184, 186, 188, 190, and 192 aresubstantially pre-fabricated as described above in association withFIGS. 8A-G, they can be assembled into a large seven layer lamination asfollows. A jig or fixture (diagrammatically depicted in FIG. 9) usingbottom and top heated platens and alignment pins can be used, such asare well known.

[0065] Detector panel 180, with surface mounted detectors 68 and printedcircuits premounted across panel 180, is placed face-up (throughappropriately positioned, pre-fabricated alignment holes 95 in panel180) onto alignment pins 94 of a lower heated lamination platen 96 (seeFIG. 9).

[0066] Next, panel 182 is superposed upon panel 180 by placing it onpins 94 so that each of its prefabricated openings 74 and 75 in each ofits sections are aligned above corresponding detectors 68 on detectorpanel 180.

[0067] Similarly, prefabricated panel 184, with pre-formed openings 66and 67 repeated at each section, is next placed on pins 94 over panel182. In turn panel 186 is placed over panel 184.

[0068] At this point, pairs of steel balls 60L and 60R are placed incorresponding ball tracks 50L and 50R in each of the sections i1 j1through iM jN. This is possible because one side of ball tracks 50L and50R are exposed at this point in the assembly process. Once all sets ofballs 60L and 60R are in place, panel 188 is placed in aligned positionon alignment pins 94 over panel 186.

[0069] Stacking of the seven panels on pins 94 is then completed byplacing panel 190 (with prefabricated openings 76L and 76R) and thenpanel 192 (with pre-installed printed circuitry and with surface mountedLEDs 62 facing down) on pins 94 in sequence.

[0070] An upper heated platen 98 is then operatively positioned onto thestack of panels on pins 94 and, by techniques well known, platens 96 and98 are moved towards each other to apply pressure to the stack. Thetemperature of both platens 96 and 98 is increased to around 175 degreesCelsius and pressure is increased to press the panels tightly together.This assembly will then remain under pressure for about an hour,allowing the heat to melt the B stage epoxy used between panel layers tobond the seven aligned panels together into a large lamination. Once thebonding process is completed, the panel assembly is allowed toappropriately cool.

[0071] After the seven-layer lamination is completed and cooled,electrical contacts 34, 36, 38, 40, and 42, on top side 30 of eachdevice 10 (as shown in FIG. 2), can be formed by drilling five holesalong the junction line between adjacent mirror-image sections (e.g.i1j1 and i2j1, or i3j7 and i4j7) (i.e. at each junction between sectionswith the SMT devices, printed circuits, and pre-formed opening mirrorimages to each other), which would expose the printed circuit lines atthose points. Plating could then be added through each of the holes,which may also extend outside the holes (see FIGS. 2A-C), using standardphoto resist metalization techniques, to form electrical connectionsneeded. At this point, it may be possible to test operability of eachdiscrete device 10 by indexing through each portion i1j1 to iMjN.

[0072] A sawing process (e.g. standard wafer sawing method) is utilizedto saw the individual laminated portions i1 j1 to iM jN from the largerlaminated panel combination illustrated in FIG. 9. When cutting throughthe drilled holes, the concave and plated portions for electricalconnects 32 would be formed for two devices 10.

[0073] In one embodiment, such a laminated panel design is used tocreate 112 individual devices 10, i.e. cut-out 112 separate sectionsi1j1 to iMjN, where, e.g., M=8; N=14).

[0074] Options and Alternatives

[0075] The above-described exemplary embodiment is set forth for exampleonly and not by way of limitation. Variations obvious to those skilledin the art will be included within scope of the invention, which isdescribed solely by its claims.

[0076] For example, other types of detectors can be utilized to indicateposition of balls 60.

[0077] It is not necessarily required that balls be utilized.

[0078] The angle of races 50 could be changed.

[0079] It may be possible to reduce the number of layers, for example,by combining the functions of certain of the layers.

[0080] Furthermore, device 10 could have one ball 60 and one lineartrack 50, to indicate one direction of tilt. On the other hand,additional balls and tracks could be utilized in one device 10, ormultiple devices 10 could be used for single camera or other object, forsensing different amounts of tilt, or even expanding to different axesof tilt.

[0081] By still further example, reference is taken to FIGS. 10-15. InFIGS. 10A and B, a single ball 60 is utilized in a single V-shaped balltrack 50. Ball track 50 has left and right branches 50L and 50R. At theupper ends of each branch 50L and 50R can be detectors, here shownsimilar to detectors 68 of the embodiment of FIGS. 1-9. The device ofFIGS. 10A and B could similarly detect tilts around 90 degrees either tothe left or right but using a single ball 60. Also, this device could bemade by the manufacturing process described previously so that aplurality of devices could be fabricated concurrently.

[0082]FIGS. 11A and B show an embodiment utilizing the V-shaped trackand single ball of FIGS. 10A and B, but utilizing one LED 62 positionedat the base of the V (adjacent to where ball 60 would be in a normalposition when device 10 is in a reference position). Photo detectors 68are positioned at the upper ends of the branches 50L and 50R.Additionally, all electrical components 62 and 68 are positioned on thesame layer, thereby reducing the number of layers upon which a printedcircuit is needed for the device. In this embodiment, when single ball60 is in it normal lower position, LED 62 would be blocked and neitherdetector 68 would receive any radiation (or enough to trigger). Thiswould be the normal non-tilted state of detector 10. When the body istilted in either direction past the amount needed to start moving ball60 along one branch of ball track 50, at the point ball 60 unblocks LED62, radiation from LED 62 would be picked up by the detector 68 in theopposite branch. Suitable programming would interpret such an output toindicate tilt of the device in the opposite direction from the detector68, which senses radiation from LED 62. As can be appreciated, byappropriate structure and thresholding, reflective principles could beused to trigger detector 68 L or R depending on which way LED lightbounces off of a single ball 60.

[0083]FIGS. 12A and B also show a single ball 60, V-shaped ball track 50arrangement but with LED 62 on a layer opposite detectors 68.Functioning should be similar to that described for the embodiment ofFIGS. 10A and B and 11A and B but would require printed circuits on twolayers.

[0084] The embodiments of FIGS. 11A and B and 12A and B could also bemade by the manufacturing process described earlier.

[0085] FIGS. 13-15 still further variations. The embodiment of FIG. 13is very similar to sensor 10 of FIGS. 1-9, but adds the feature ofhaving openings or apertures 56L and R towards the bottom of ball tracks50L and R. Openings 56L and R are sized to be smaller than the diameterof ball 60, but allow a ball 60 to seat therein if sensor 10 is rotatedaround its X-axis such that its X-Y plane approaches horizontal (e.g. inthe digital camera example, the lens of the camera is turned face downor face up. Balls 60L and R would seat within openings 56L and R andwould be deterred from rolling or moving to the opposite ends of balltracks 50L and R and triggering one or more photodetectors 68L and R, asthis could confuse camera 12 or the operator, or would provideinformation that is not very useful when the camera is in that position.

[0086]FIG. 14 illustrates one ball track 50 of diamond shape, with oneball 60. This embodiment works similarly; it can detect a substantialtilt left or right from reference position. It could detect such tilteven if upside down. It also includes a channel or opening 57 that wouldwork like openings 56 of FIG. 13. If sensor 10 is rotated substantiallyface down or face up (around the X-axis), ball 60 would tend to seatinto channel 57 and not roll around ball race 50 and trigger eitherphotodetector.

[0087]FIG. 15 is similar to FIG. 14, but instead of a diamond shapedball race 50, has predominantly a v-shape (similar to FIGS. 10-12). Butit does include a central roundedout extension 58 sized to receive ball60. Then, if sensor 10 is turned substantially upside down, ball 60would be forced by gravity into extension or cupped portion 58 and heldagainst movement to trigger either detector 68. It could also includechannel 57, like the embodiment of FIG. 14.

[0088] Each of the embodiments can be fabricated using the laminationmethodology described above.

[0089] Other arrangements are, of course, possible. These examples areprovided simply to illustrate variations and changes from the embodimentof FIG. 1-9 are included within the scope of the present invention.

What is claimed is:
 1. A tilt sensor comprising: a body; a space in thebody; a member positioned in the space, the member moveable between atleast two positions within the space under the influence of gravity whenthe body is rotated about an axis; a detector in the body adapted todetect when the member is in one of the two positions.
 2. The tiltsensor of claim 1 wherein the body is less than one inch square involume.
 3. The tilt sensor of claim 1 wherein the space is enclosedwithin the body.
 4. The tilt sensor of claim 1 wherein the membercomprises a ball.
 5. The tilt sensor of claim 4 wherein the spacecomprises a race with opposite ends.
 6. The tilt sensor of claim 5wherein the race is generally linear.
 7. The tilt sensor of claim 5wherein the race is generally non-linear.
 8. The tilt sensor of claim 1wherein the detector comprises a photo optical detector.
 9. The tilt ofclaim 8 wherein the photo optical detector comprises a light emitter anda light detector.
 10. The tilt sensor of claim 9 wherein the lightemitter is adapted to direct light into the space and the light detectoris adapted to receive light from the space.
 11. The tilt sensor of claim1 further comprising a second space, a second member within said secondspace, and a second detector adapted to detect when the second member isin one of two positions in the second space.
 12. The tilt sensor ofclaim 11 wherein the members comprise balls and the space comprisesraces.
 13. The tilt sensor of claim 12 wherein the races are arrangedangularly relative to one another.
 14. The tilt sensor of claim 13wherein the races are at acute angles relative to a reference linethrough the body.
 15. The tilt sensor of claim 14 wherein the acuteangle comprises approximately 55°.
 16. The tilt sensor of claim 1wherein the detector comprises one emitter and two receivers.
 17. Thetilt sensor of claim 16 wherein the receivers are at or near distal endsof the opening.
 18. The tilt sensor of claim 17 wherein the opening hastwo branches, each path comprising a path from the member to move. 19.The tilt sensor of claim 18 wherein the path of each branch oriented atan angle relative to a reference plane of the body.
 20. The tilt sensorof claim 1 wherein said body is manufactured by laminations.
 21. Thetilt sensor of claim 20 wherein said laminations include a said spacepreformed in said layer.
 22. The tilt sensor of claim 21 furthercomprising layers positioned on opposite sides of said layer includingsaid space and said member, at least one of said layers including saiddetector.
 23. The tilt sensor of claim 1 wherein said body is created bylaminations, the laminations comprising a first layer with a photodetector, a second layer with an opening corresponding with said photodetector, a third layer containing said space, a fourth layer with anopening and a fifth layer including a photo emitter positioned incorrelation with the opening.
 24. The tilt sensor of claim 1manufactured from a plurality of tilt sensors con-currently constructedby lamination layers and assembly, and separated into discrete bodies.25. The tilt sensor of claim 24 wherein the discrete bodies are createdby cutting away portions of the lamination.
 26. The tilt sensor of claim1 wherein the opening comprises a path between said two positions, thetwo positions near or along a line which is angularly offset from areference line.
 27. The tilt sensor of claim 26 wherein the angularoffset is correlated to the amount of tilt to detect.
 28. The tiltsensor of claim 27 wherein the angular offset is approximately 55°. 29.The tilt sensor of claim 1 wherein the detector comprises electricalconnections, the electrical connections being integrated into the body.30. The tilt sensor of claim 1 wherein the detector is adapted forcommunication with another device.
 31. The tilt sensor of claim 1wherein the tilt sensor indicates an angle of the body with respect togravity.
 32. A method of making a plurality of tilt sensors comprising:fabricating a layer having a length and width and thickness, andpartitioned into a plurality of areas, each area including an openingthrough the layer; placing moveable members into the openings in saidlayer; positioning additional layers over and under said layer tocapture the members yet allow movement between at least two positions inthe opening, at least one of said additional layers having integratedthereon at least one of a photo emitter or detector aligned at eachopening; adhering the PCBs together to form a laminated set of aplurality of tilt sensors; cutting out each of the plurality of areas.33. The method of claim 32 wherein said additional layer comprise afirst PCB, a spacer PCB and an aperture PCB.
 34. The method of claim 32wherein the additional layers include openings.
 35. The method of claim32 wherein the member comprises a ball.
 36. The method of claim 32wherein the member comprises a pendulum.
 37. A method of manufacturingan inclinometer comprising: providing a first PCB; superposing a secondPCB, including an open area, on the first PCB; placing a member,moveable within the open area in response to gravity, within the openarea; superposing a third PCB on the second PCB to capture the memberbetween the first and third PCBs, the member moveable by gravity betweenpositions in the open area; the first or third PCB including apre-installed emitter, the emitter being pre-wired and adapted to emitlight into the open area at one of the positions in the open area whencombined with the other PCBs; the first or third PCB including apre-installed detector of light from the emitter, the detector beingexposed to the open area when combined with the other PCBs; and each PCBincluding adhesive and activating the adhesive when the PCBs aresuperposed relative to one another to form a lamination of said PCBs.38. The method of claim 37 wherein each PCB includes a plurality ofcorresponding open areas, members, emitters and detectors on a pluralityof sections of respective PCBs which are positioned to be aligned whenthe PCBs are superposed.
 39. The method of claim 38 further comprisingseparating the lamination of PCBs by said sections.
 40. The method ofclaim 39 further comprising creating electrical connections for eachseparated section adapted for electrical communication with anotherdevice.